The Islamic Republic claims that it is fighting Islamic State (IS)—and has done so occasionally—but in reality it has benefited immensely from the terrorist group’s rise. The more chaos IS causes, the more opportunity Tehran has to further its quest for regional hegemony, as Ray Takeyh and Reuel Marc Gerecht write (free registration required):

Iran is using Islamic State’s ascendance in the Middle East to consolidate its power. The country is now the key ally keeping Iraq’s Shiites and the Alawite Bashar al-Assad regime standing against well-armed and tenacious Sunni jihadists. In those battles, Tehran will likely do just enough to make sure the Sunnis don’t conquer the Shiite portions of Iraq and Assad’s enclave in Syria, but no more. Meanwhile, . . . Tehran will strengthen its own radical Shiite militias.

The result could be a permanent destabilization of the Arab heartland. That would be a major victory for the Islamic Republic, which has seen its fortunes rise as Egypt and Turkey have become mired in crises and as Saudi Arabia, Iran’s one remaining serious Sunni rival, has gotten bogged down in a war in Yemen. . . .

If Sunni radicals were to establish terrorist cells inside Iran’s minority Sunni communities, Tehran might want to throttle IS. Barring that eventuality, however, the clerical regime has no interest in diminishing the sectarian bloodbath that has allowed it more influence than at any time since the 1979 revolution. At best, anti-Americanism brought Tehran fellow-travelers; IS, however, has given the regime its best shot at an empire. For Iran’s ruling elite, Shiite-hating Sunnis have never looked so good.

Early Friday morning, Israel attacked military installations near the Iranian cities of Isfahan and nearby Natanz, the latter being one of the hubs of the country’s nuclear program. Jerusalem is not taking credit for the attack, and none of the details are too certain, but it seems that the attack involved multiple drones, likely launched from within Iran, as well as one or more missiles fired from Syrian or Iraqi airspace. Strikes on Syrian radar systems shortly beforehand probably helped make the attack possible, and there were reportedly strikes on Iraq as well.

Iran itself is downplaying the attack, but the S-300 air-defense batteries in Isfahan appear to have been destroyed or damaged. This is a sophisticated Russian-made system positioned to protect the Natanz nuclear installation. In other words, Israel has demonstrated that Iran’s best technology can’t protect the country’s skies from the IDF. As Yossi Kuperwasser puts it, the attack, combined with the response to the assault on April 13,

clarified to the Iranians that whereas we [Israelis] are not as vulnerable as they thought, they are more vulnerable than they thought. They have difficulty hitting us, but we have no difficulty hitting them.

Nobody knows exactly how the operation was carried out. . . . It is good that a question mark hovers over . . . what exactly Israel did. Let’s keep them wondering. It is good for deniability and good for keeping the enemy uncertain.

The fact that we chose targets that were in the vicinity of a major nuclear facility but were linked to the Iranian missile and air forces was a good message. It communicated that we can reach other targets as well but, as we don’t want escalation, we chose targets nearby that were involved in the attack against Israel. I think it sends the message that if we want to, we can send a stronger message. Israel is not seeking escalation at the moment.